Objective:  We examined the Y-27632 impact of estradiol and progesterone on skin LH and RH in 25 healthy women. Methods: 

Subjects were studied three times over 10–12 days. Endogenous sex hormones were suppressed with a GnRHa. Subjects were studied on day 4 of suppression (study day 1), three to four days later following treatment with either 17β-estradiol or progesterone (study day 2), and another three to four days later, following treatment with both estradiol and progesterone (study day 3). Subjects underwent identical LH and RH protocols on all study days. LH is characterized by an initial peak in blood flow, followed by a prolonged plateau. A brief nadir is seen between the phases. Results:  Blood flow values are expressed as percent maximum CVC. Estradiol alone increased initial peak CVC from 71 ± 2% to 79 ± 2% (p = 0.001). Progesterone alone increased initial peak CVC from 72 ± 2% to 78 ± 2% (p = 0.046). Neither estradiol nor progesterone increased plateau CVC. No significant changes were seen between study days 2 and 3 for either group. No differences were observed in RH. Conclusions:  Both estradiol and progesterone increased initial peak CVC during LH, without altering plateau CVC. There was no additive effect of estradiol and progesterone. “
“Astrocytes are thought to play an important role in neurovascular coupling, a process that allows the brain

to locally control blood flow in response find more to changes in activity. However there is ongoing debate as to when, and under what conditions astrocyte activity is required. In the following review we set forth the hypotheses that astrocytes: 1) act to modulate but not initiate functional hyperemia, and 2) help set the basal tone state of the brain microvasculature by the tonic release of vaso-active messengers. Through these actions astrocytes could help match metabolic demand with supply over a spectrum of activity timescales. This article is protected by copyright. All rights reserved. “
“We studied the effects of S1P on the

diameter and spontaneous contraction of murine iliac collecting lymph vessels. The isolated lymph vessel was cannulated with two glass micropipettes and then pressurized to 4 cmH2O at the intraluminal Bacterial neuraminidase pressure. The changes in lymph vessel diameter were measured using a custom-made diameter-detection device. Immunohistochemical studies were also performed to confirm S1P receptors on the lymph vessels. S1P (10−7 M) had no significant effect on the frequency or amplitude of the lymph vessels’ spontaneous contractions. In contrast, S1P (10−8–10−6 M) produced a concentration-related reduction in lymph vessel diameter (tonic contraction). Pretreatment with 10−4 M l–NAME or 10−5 M aspirin had no significant effect on the S1P-induced tonic contraction of the lymph vessels.